"UV is invisible so it doesn't matter how dark or what colour sunglasses are," Sutton told HuffPost Australia.

"You can have a very dark pair of cosmetic glasses, and you might feel as though there's not much light getting in, but it's not visible light that's potentially dangerous, it's UV that you want to filter out."

He said lighter lenses, whether they were grey, green, brown or any other colour, were just as effective.